A new CDC study found 5% of infants or fetuses born to women in the U.S. with laboratory-confirmed Zika infections had microcephaly or another Zika-linked birth defect.

"The bottom line is that Zika infection, identified during any trimester of pregnancy, can lead to serious brain and other birth defects," said Peggy Honein, an author on the study.

What they found: Infants developed microcephaly and other birth defects regardless of whether or not the mother displayed symptoms. The data also showed that babies infected in all trimesters exhibited birth defects, but the earlier the infection occurred, the more likely they were. Rates ranged from 8% for infants infected in the first trimester to 4% in the third.

Unanswered questions: There are reported cases of Zika-infected mothers having babies that appear normal at birth, but develop microcephaly and neurological difficulties as they age. Because this study looked at newborns, these cases are not included.

Go deeper: Much of the research linking Zika to microcephaly has been done in South America. This study confirms that those cases were due to the Zika virus, and not due to an interaction of the virus with something genetic or environmental in the area. The size (2549 people) and rigor of the study was also important, as past research on Zika-related birth defects has ranged in quality and given prevalence rates ranging from 1-13%. This was one of the first studies to break down infections by trimester and whether or not the mother was asymptomatic.

Go deeper

Exclusive: Conservative group launches $2M Supreme Court ad

Screengrab of ad, courtesy of Judicial Crisis Network.

The Judicial Crisis Network is launching a $2.2 million ad campaign to put pressure on vulnerable Senate Republicans in battleground states to support a quick confirmation when President Trump announces his Supreme Court nominee.

The big picture: "Follow Precedent," previewed by Axios, is one of the first national and cable television ads to run following Justice Ruth Bader Ginsberg's death Friday.

Updated 15 mins ago - Politics & Policy

CDC says it mistakenly published guidance about COVID-19 spreading through air

CDC Director Robert Redfield. Photo: Anna Moneymaker/Pool/Getty Images

The CDC has removed new guidance that acknowledged airborne transmission of the coronavirus, posting in a note on its website that the guidance was only a draft and had been published in error.

Why it matters: The initial update — which was little noticed until a CNN story was published Sunday — had come months after scientists pushed for the agency to acknowledge the disease was transmissible through the air. The CDC previously said that close person-to-person contact was the bigger concern, and the language has been changed back to erase the warning about airborne transmission.

Ruth Bader Ginsburg will lie in state in Capitol's National Statuary Hall

Photo: Getty Images

House Speaker Nancy Pelosi announced Monday that the late Supreme Court Justice Ruth Bader Ginsburg will lie in state in the Capitol's National Statuary Hall on Friday.

The state of play: The Supreme Court also announced Monday that Ginsburg will lie in repose on the front steps of the building on Wednesday and Thursday, allowing the public to pay respects to the late justice outside.